Preventing draft in coal-mines



(No Model.) 1

I E. A. TIFFANYT PREVENTING DRAFT IN COAL MINES.

Patented Dec. 4, 1894.

I711) e 7% I UNITED STATES PATENT OFFICE.

ERNEST A. TIFFANY, OF DUNMORE, PENNSYLVANIA.

PREVENTING DRAFT IN COAL-MINES.

SPECIFICATION forming part of Letters Patent No. 530,463, dated December 4, 1894. Application filed April 3, 1394. Serial N0. 506,166. (No model.)

To all whom it may concern.-

Be it known that I, ERNEST A. TIFFANY, a citizen of the United States of America, residing at Dunmore, in the county of Lackawanna and State of Pennsylvania, have inventedcertain new and useful Improvements in Preventing Draft in Goal-Mines, of which the following is a specification.

My invention relates to doors for coal mines. They are designed for the purpose of closing the chambers to prevent the passage of air or foul gases.

The object of the special construction hereinafter described is to provide mechanism whereby the doors may be opened and closed by the passage of the car while at the same time the doors are heldfirmly and prevented from being opened by the pressure of the current.

The invention is illustrated in the accompanying drawings, in which- Figure 1, shows the track and gate with the opening and closing devices in side elevation.

Fig. 2, shows an end view. Fig. 3, shows a plan view. Fig. 4, shows detail views of the tripping device. Figs. 5 and 6 show a modified form of the means operated by the wheels of the truck.

In the drawings I have shown an ordinary rail way track suitable for a coal mine. Across it is placed a double door A A, the valves of which are fixed to vertical shafts b, the lower ends of which are stepped in suitable bearings. The upper ends have their bearings in a cross piece 0 supported on posts (1 orin any suitable way. The doors are rabbeted on their free edges; and the rabbets are arranged to overlap, as shown in Fig. 3. At the lower endsof the shafts are fixed gears e, which mesh with segments f fixed to a transverse shaft 9. One segment is on the outside and the other on the inside of the gears e, this arrangement being for the special purpose of turning the valve shafts in opposite directions bythe same movement of the segments and also to hold the doors in ,a closed position against pressure thereon. The segment on one side is connected to cranks 3, 4. by rods h h, one being connected above the crank shaft and the other below. These crank shafts have each two small wheels or disks m m fixed thereto just inside of the rails. By the side of each of the said cam disks m m, an arm is placed, those marked as being for the wheels as X on the rail Y while those marked w are for the wheels on the other rail Y.

The arms are cut away so as to partially overhang the wheels, their movement about their axles being limited by studs 1-2 each disk having a pair of said studs. The arms w are drawn normally back away from the other side of the same axle moving along the rail Y will at the same time strike the arm to but as this is held away from the door and against its outermost stop it will have a certain amount of 10st movement before reaching its other stop pin as at 1, on the right of Fig. 3, and this free play or lost motion is sufficient to permit the wheel on rail Y to pass over the arm to depressing the same without effect on the doors. This wheel however, on the rail Y will strike the arm w on the left of the doors and as this is in contact with its stop 2 this arm will move with the disk mas one thus closing the doors by moving the segment in the opposite direction. At the same time the wheel X which operatesthe doors in r the first instance by striking thearm w on the right of the doors will now strike the arm w on the left and as this arm has free play away from the doors it will simply be depressed without elfect on the disk mand the connections leading to the doors.

The wheelsof the car running in the opposite direction will operate in precisely the same way in reverse directions on the levers.

It will be apparent that the current of air pressing upon the doors would tend to hold them in a fixed position since the pressure will be the greater on the overlapping door which opens against the current and one door holds the other.

In Figs. 5 and 6 I have shown in detail a modification of the arm to be struck by the wheel and the disk or wheel supporting it.

In this form the disk is provided with a circular depression 7 and witha projection 10 forming a stop shoulder 9. The arm 8 turns on the end of the shaft is which projects through the disk and in the recess 7 a coiled spring 12 is placed connected to the disk and to the arm 8 to hold it in normal position. The arm is in position to contact with the stop shoulder 9 and turn the disk when the arm is struck by the wheel.

In Fig. 5, a part of the disk is shown as broken away in order to show the spring in the circular depression.

I claim- 1. A pair of doors mounted upon vertical shafts and arranged to open in opposite directions, the said doors being geared to segments on the same shaft, arranged to open the doors in opposite directions by one movement of said shaft, one of said segments being connected with mechanism operated by the car, all substantially as described.

2. In combination with the doors geared to a shaft and arranged to open in opposite directions by the same movement of said shaft, the spring arms x, w, a crank shaft and rods connecting the cranks with a segment on the door shaft, substantially as described.

In testimony whereof Iaffix my signature in presence of two witnesses.

ERNEST A. TIFFANY.

Witnesses: 1

G. H. CUMMY,

CELIA E. TIFFANY. 

